Haemolytic disease of the newborn--the changing scene.

Between 1950 and 1970 there was a steady decline in the number of infant deaths from rhesus haemolytic disease of the newborn in the Yorkshire Region but no decrease in the number of pregnant women with antibodies. Following the introduction of Rh prophylaxis in 1970, the number of pregnant women sensitized has decreased by 70% and the number of infant deaths by 96%. The number of infants requiring exchange transfusion has also decreased by 70%. During the years 1980 to 1983 there were 163 new cases of maternal sensitization to the D antigen in the Yorkshire Region, 36 were due to failures of administration, 75 were failures of protection and 26 were in primigravidae. Eighteen of the failures of administration occurred after abortion, nine of which were surgical terminations. Antenatal prophylaxis may well have protected 64 (40%) of these 163 women. The number of pregnant women with antibodies other than anti-D now exceeds those with anti-D. The effect of these changes in incidence and clinical severity on the management of Rh D negative pregnant women is discussed.